64129381 has 2 divisors, whose sum is σ = 64129382. Its totient is φ = 64129380.

The previous prime is 64129379. The next prime is 64129409. The reversal of 64129381 is 18392146.

64129381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36409156 + 27720225 = 6034^2 + 5265^2 .

It is a cyclic number.

It is not a de Polignac number, because 64129381 - 2¹ = 64129379 is a prime.

It is a super-2 number, since 2×64129381² = 8225155014886322, which contains 22 as substring.

Together with 64129379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64129301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32064690 + 32064691.

It is an arithmetic number, because the mean of its divisors is an integer number (32064691).

Almost surely, 2^64129381 is an apocalyptic number.

64129381 is the 4281-st centered heptagonal number.

It is an amenable number.

64129381 is a deficient number, since it is larger than the sum of its proper divisors (1).

64129381 is an equidigital number, since it uses as much as digits as its factorization.

64129381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 34.

The square root of 64129381 is about 8008.0822298475. The cubic root of 64129381 is about 400.2693623191.

The spelling of 64129381 in words is "sixty-four million, one hundred twenty-nine thousand, three hundred eighty-one".